1, causing cardiovascular diseases. Caffeine is the main substance in coffee. Caffeine is an active substance, which can accelerate the heart rate and raise blood pressure. If you drink a lot of coffee for a long time, it may lead to cardiovascular disease.

2, gastrointestinal diseases. Some ingredients in coffee will increase the secretion of gastric acid in the stomach and stimulate the gastric mucosa. Excessive drinking may also lead to gastric ulcer, especially drinking coffee on an empty stomach, which is more harmful to the stomach.

3, carcinogenic. Coffee may cause cancer, which often happens when coffee beans are stale or moldy. Drinking this coffee for a long time will cause cancer.

4. nervous. Moderate drinking coffee is good for the brain, but long-term excessive drinking will cause excitement, which is harmful to patients' brain nerves and may cause anxiety and other adverse symptoms.